Total 125$ per month. The only way I see it lucrative to renters is if they are gambling and thinking, it will be another bitcoin. In case of no renter is interested, who is hosting all these files and providing this?

When you say renters, and I read you post I think you mean hosts? Host generate income by hosting. Renters hire space and generate savings compared to having the files stored locally, asuiming the "race towards the bottom" will ensure the cheapest storage around.

However... Look at the utilizatoin. It is low..
Look at the price fluctionations for the price of the SIAcoin - it is high as all cryptos since they at the moment serves no other function than pure speculation - that is a fact.

I think you will se at least two types of hosts:

the little privat hosts having a few TB to spare and making a small profit - if you read the initial idea behind SIA it was to compile all those little spaces into one big that could be shared and capitalized.

then you will have larger semi/proff hosts providing a lot of storage.

Imo currently there are no economical viable incentives to engage in hosting in any of the above cases due to the weak demand. Also, the technology, especially the client is un marute, and unstable and needs too much care to make it to the market. You can also factor in, it is totally unkonwn what your earnings in fiat will be, since you normally lock up your contracts for 26 weeks and that is a life time in crypto introducing big swingds in price. I can't see how any corporations either on demand/supply side can cope with that risk?

There are many posts around it - I'll point out a few, I've been engaged in: